Generally the ground surface or contact with overlying Peat, Head (Severn and Avon Catchments and West Wales Catchments subgroups). Near Llanrhystud it is overlain by red sandy diamicton of the St Asaph Glacigenic Formation (see Campbell and Bowen, 1989; Davies et al., 1997)

Thickness:

Highly variable, locally in excess of 30m

Geographical Limits:

Mid and west Wales, southwest Wales approximately west of Swansea and including the Gower.

Coastal section between Morfa Bychan and Mynachdy'r-graig in Cardigan Bay (Ceredigion) exposing up to 40 m of drift overlying, and blanketed against, a pre-Devensian 'fossil cliff'. A basal Head deposit is sharply overlain by up to 30 m of glacial deposits of the Elenid Till Member (Plynlimon Glacigenic Formation)exhibiting evidence of solifluction, itself sharply overlain and overstepped by Head and Loess. Campbell and Bowen, p.63-65 (1993); Davies et al. (1997)